Electric switch



May 19, 1925. 1,538,671

L. STENDAHL ELECTRIC SWITCH FiledV April 22, 1920y www STE/mmm Patented May 19, 1925.

UNITED STATES l 1,538,671 PATENT OFFICE.

LUDWIG STENDAHL, 0F FAIRFIELD, CONNECTICUT, ASSIGNOR T0 TIHIE BRYANT ELECTRIC COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION 0F CON- NECTICUT.

ELECTRIC SWITCH.

Application med Apri122, 1920. serial No. 375,765.

To all whom it may concern.:

Be it known that I, LUDWIG STENDAHL, a subject of the King of Sweden, residing at Fairfield, in the county of Fairfield and State of Connecticut, U. S. A., have 'invented certain new and useful Improvements in Electric Switches, of which the following is a specification.

My invention relates to electric switches,

and particularly to an electric snap switch;

The object of my invention is to provide a simple and efficient construction, the mechanism of which is such as to afford a wide break between the contacts on the opening of the switch, while nevertheless maintaining a compact arrangement of the parts. The switch in the form shown is designed for. installation in a tubular casing, such as the handle of a vacuum cleaner, or -the like, although many of the features of the construction are readily adapted to switches of other types.

In the accompanying drawings- Fig. 1 is a longitudinal section through a switch in which my invention is embodied in one form, but drawn to an enlarged scale;

Fig. 2 is a plan view thereof;

Fig. 3 is a detached perspective .of the switch mechanism; l

Fig. 4 is a partial section through the switch frame casing illustrating a'modied form of construction.

The casing of the switch is here shown as the tubular handle 5 of a vacuum cleaner.

The switch frame comprises a pair of parallel insulating plates 6 and united by metal spacers 8 and 9. The cross bars 10 and 11 of the spacer 8 are tapped at 12 and 13 to receive securing screws 14 passed through holes in the tubular casing 5. An insulating lining 15 for the casing is preferably provided. The dimensions of 'the frame are so predetermined with respect to the diameter of the tube 5 that the spacer 9 rests against the opposite side of the'tube from the spacer 8 and affords a support which assists the screws 14 in holding the frame in position, while the ends of the side plates are rounded to permit the switch to be installed at a curve in the tubular handie, if desired. Atone end of the side plates 6 and 7 are riveted wire terminals 16 and 17, which carry the odset spring contact wings 18and 19.

The switch mechanism comprises a bell .crank rocker, one arm 20 of which extends through a slot 21 in the casing 5 and is provided with a suitable thumb piece 22 at its outer end, by which it may be operated. The rocker is formed from a pair of plates riveted together at 23, but offset at 24 to afford a `pair of parallel legs 25, pierced at 26 to receive the pivot pin 27, on which it is supported. Extending substantially at right angles to the length of the arm 20 are the bell crank arms 28 notched at 29 to engage the switch spring abutment 30. A cross pin 31 fastened between the side plates 6 and 7 passes through a slot 32 formed in the arms 28 and thus limits the throw of the rocker. n.

Straddled by the bell crank arms 28 of the rocker is a plate-like switch lever 33 carrying at one end the cross bar 34, which is adapted to span the switch contacts 18 and 19, and thus close the circuit through the switch. This lever 33 is centrally aper-v tured at 35 and'shouldered at 36 to support an abutment plate 37, against which one end of the switch spring 38 thrusts. spring guideI pin 39 passes at one end through the plate 37 (and at its other end has a cross head abutment 30) which is engaged by the ynotches 29 of the bell crank arms 28.u An open bearing notch 40 at one end ol the aperture 35 receives the bearing pin 31 against which the lever is ,held by the pressure of the switch spring 38,. and on which it rocks when the spring abutment 30 is swung from one side thereof to the other by the actuation of the bell crank 20. The aperture 35 is so shaped and of such dimensions that the spring 38, which works therein in the plane of the switch lever, has ample clearance, while the throw of the bell crank arms 28 is sufficient to carry the cross pin abutment 30 and the end of the spring guide pin 39 over the bearing pin 31 without interference, Outwardly projecting lugs 41 at the bearing end of the lever 33 engage the spacing thimble 42 on the bell crank pivot-pin 27 and thus limit the throw of the switch lever.

As here shown the switch lever is laminated and comprises a metal, plate 43 flanked by sheets of insulation 44. The latter extends beyond the metal plate 43 at the switch bar end and thus serve to lengthen and break the arc which tends to The forni between the switch contacts 18 and 19 on the opening movement-of the switch.

In Figs. 1, 2 and 3 the side plates 6-and 7 of the frame are shown as of insulation throughout. Where the spacers 8 and 9 are secured by turned over or riveted ends, as in the construction shown, it is advisable to face the insulation by metal plates 45 (Fig. 4) to afford a more rigid surface against which the heads of the rivets or turned over lugs may be forced down. In this construction the wire terminal plates would be insulated vby suitable bushings i6 from their securing rivets 47.

The operation of the switch is readily understood. Vhen the lever 20 is swung to the position indicated in dotted lines .in Fig. 1, its bell crank arms 28 shift the spring abutment 30 from one side to the other of the bearing pin 3l for the switch bar 33. As soon as the abutment 30 passes the axis of oscillation 31, the switch spring 38 exerts its force in the opposite direction and now, further tensioned, throws the switch lever to the off position. The return movement of the level' 20 reverses the operation and again establishes the circuit between the terminals 18 and 19.

Obviously the switch mechanism is not limited in its utility to tube switches, and many of its features may be embodied in switches of entirely different type. The details of construction may also be variously modified without departing from what I claim as my invention, the above description and accompanying drawing being understood to be merely illustrative.

I claim- 1,. In an electric switch, a switch frame comprising parallel insulating side plates, brackets extending between said plates to space the same apart, pivot means independent of the brackets and extending between said side plates and switch mechanism mounted on said pivot means between the side plates.

2. In an electric switch, a switch frame comprising laminated side plates, the outer faces of which are metallic, and the inner faces of which are insulation, in combination with metallic spacing brackets extending between said side plates and having lugs passing therethrough and odset at their outer ends against said metallic facing for the side plates to secure the brackets in position.

3. In an electric switch,'a switch frame comprising rigid side plates of fibrous insulating material, spacing brackets extending between the same and secured thereto, wire terminals mounted against the faces of said insulating side plates, securing means passing therethrough to hold the terminals in position, and a metallic member lying 'against the opposite faces of the plates to form rigid abutments against which the securing means may be deformed under pressure without injury to the insulating material of the side plates.

' 4. In an electric switch, a switch frame comprising rigid side plates of iibrous insulating material, spacing brackets extending between the same and secured thereto, wire terminals mounted against the faces of said insulating side plates and extending beyond the ends thereof to exposed position for wiring, associated switch contacts extending into the area between said side plates, and means for securing the wire terminals and switch contacts to said side plates.

5. In an electric switch, a switch frame comprising insulating side plates, metallic spacing brackets extending between the same and secured thereto, switch mechanism mounted on said insulating side plates, a tubular casing for said frame, and bracket engaging means to secure the frame within said casing.

6. In an electric switch, a switch frame comprising insulating side plates, metallic spacing brackets extending between the same and secured thereto, a switch mechanism, -and means independent of the brackets for mounting the same on said side plates, a tubular casing, bracket engaging.

means for securing the frame within said casing, and switch operating means projecting through said casing.

7 In an electric switch, a switch frame comprising insulating side plates arranged substantiallyin parallel, bracket means for spacing the same apart, wire terminals secured to but projecting beyond one end of the insulating side plates, a tubular casing and an insulating lining therefor extending beyond the wire terminals, and means engaging the spacing brackets to mount the switch frame within the casing.

8. In an electric switch, a tubular casing, a switch frame mounted therein, ajswitch bar pivoted on said frame and having a throw across the axis of the casing, a bell crank rocker independent of the switch bar and pivoted on said frame, one arm of said bell crank passing through the casing and having a throw parallel with'the axis of the latter, the second arm of the bell crank rocker having a throw across the axis of the casing, in combination with a switch spring operatively interposed between said second arm of the bell crank lever and the switch bar.

9. In an electric switch, a tubular casing, a switch frame mounted therein, a switch bar pivoted on said frame and having a throw across the axis of the casing, a bell crank rocker independent of the switch bar and pivoted on said frame, the axes of said switch bar and rocker being transverse to llO the axis of the casing and longitudinally spaced substantially on said axis, one arm of said bell crank passing through the casing and having a throw parallel with the axis of the latter, the second arm of the bell crank rocker having a throw across the axis of the casing, in combination with a switch spring operatively interposed be-v tween said second arm of the bell crank lei-'er and the switch bar.

10. In an electric switch, a tubular casing, a pivoted switch bar extending longitudinally of the casing, but having a throw transverse to the axis thereof, in combination with a bell crank rocker pivoted on an axis spaced, longitudinally of the casing axis, from that of the switch bar, one arm of which is operatively associated with said switch bar, and the other arm of which passes through the side wall of the casing to position for manual operation.

11. In an electric switch, a tubular casing, a pivoted switch bar, a rocker separate therefrom and pivoted on an independent axis, the axes of said switch bar and rocker beinglocated approximately in an axial plane through thel casing, but at right angles to the longitudinal axis thereof, said rocker forming a bell crank, one arm of which is operatively associated with the switch bar, and the other arm of which passes through ythe side wall of the casing for manual operation.

12. In an electric switch, a tubular casing, a switch frame supported by the side wall of said casing, a snap switch mechanism mounted in said frame'and comprising a bell crank lever, one arm of which has means for engaging a cooperating element of the switch mechanism, andthe other arm of which projects through the side wall of the casing and is provided with a thumb piece to facilitate manual operation thereof together with a switch element oper'- atively connected to the inner arm of the bell crank lever and pivoted on an axis transverse to the axis 4of the casing, but spaced from the axis of the bell crank longitudinally of the casing.

13. In an electric switch, a bell crank rocker, one arm of which is notched to form an open bearing for a cooperating element of the switch rocker, and the other arm of which is provided witha thumb piece to facilitate manual operation, one of said arms being apertured to receive a stop limiting the throw ofthe rocker.

14.' In an electric switch, a switchmechanism comprising a pivoted, apertured plate constituting the switch bar,l aswit'ch spring arranged in said aperture and displaceable in the plane of said plate from one side to the other of the axis of oscillation of the plate, an` abutment on the plate for one end of said spring, and a movable abutnient for the opposite end of said spring for shifting the'latter.

15. In an electric switch, a switch mechanism comprising an apertured plate constituting a switch bar, an open bearing formed at one end of the aperture therein, a switch spring abutment at the other end of-said aperture, a switch spring seated at one end against said abutment, in combination with a movable abutment` for the other end of said spring, and means for swinging said movable abutment from one side to the other of said open bearing.

16. In an electric switch, a switch mech- "anism comprising an apertured plate constituting a switch bar, an open bearing formed at one end of the aperture therein, a switch spring abutment at the other end of said aperture, a switch spring seated at one end against said abutment, in combination with a movable abutment for the other end of said spring, and a rocker straddling said switch bar plate and engaging said abutment to swing the latter from one side to the other of said open bearing.

17. In an electric switch, a pivoted switch bar plate, a switch block carried thereby and extending transversely thereto, and insulation constituting a portion of said switch bar plate and extending in the plane thereof beyond theswitch block for thepurpose described.

18. In an electric switch, a laminated switch bar comprising juxtaposed metallic and insulating plates, the latter forming the exposed sides of the switch bar in combination with a switch block mounted in said bar and extending beyond the sides thereof.

19. In an electric switch, a switch bar plate centrally apertured to accommodate a switch spring, an open bearing formed at one end of said aperture, exterior lugs adapted to cooperate`with a stop, and a switch block extending transversely to the Vplate and carried thereby.

20. In an electric switch, a switch frame comprising a pair of spaced plates, a pair of pivot pins extending between said plates, a switch 'bar' pivoted on one of said pins, a rocker pivoted on the other of said pins, an operating connection between said rocker and switch bar, the pivot pin of the rocker serving as a` stop to limit the throw of the switch bar, while the pivot pin of the latter serves as a stop to limit the throw of the rocker. A

21. In an electric switch, a switch frame comprising a pair of spaced sidev plates, a pair of pivot pins extending between the same, a tubular casing surrounding the frame and secured thereto, a bell crank rocker pivoted on one of said pins, and having one arm' extending outthrough the casing for manual operation, a switch bar plate pivoted on the second of said pivot pins and straddled by the other arm of the bell crank lever, said switch bar plate being apertured, a switch spring arranged in said aperture and abutting at one end against the switch bar plate, a movable abutment for the other end of said spring, means on the inner arm of the bell crank to engage Said movable abutment to shift` the same from one side to the other of the pivot pin upon 'which the switch bar bears, and means limiting the throw of said rocker and switch bar respectively.

22. An electric switch comprising a pivoted switch bar, a pivoted bell crank operating lever having a manually operated arm and a switch bar actuating arm, an `operating spring connection between the actuating arm and switch bar, the mid radius of the arcuate throw of the switch bar lying substantially at right angles to the mid radius of the arcuate throw of the actuating arm of the switch lever, While the mid radius of the actuating arm of the rocker is substantially coincident with that of the switch bar.

23. In an electric switch, a pivoted bell crank lever having a manually operated arm 'and a switch bar actuating arm, in combination with a switch bar pivoted on an independent axis, -a spring connection between the actuating arm of the bell crank lever and the switch, said actuating arm of the bell crank and the lever switch bar having throws on intersecting arcs, the mid radii of which are substantiall normal to the mid radius of the throw of t ie manually operated arm of the bell crank.

In testimony whereof I have signed my name to this specification.

LUDWIG STENDAHL. 

